Some 600 people were evacuated from their homes in Frankfurt as bomb disposal experts could remove a World War II-era bomb.
According to media reports, the bomb was defused underwater on Sunday, leading to a loud detonation and a big water fountain.
The 250 kg bomb was detected by divers with the city's fire service during a routine training exercise in Frankfurt's River Main.
Even more than 70 years after World War II, bombs and other munitions are still detected in several parts of Germany.

Earthquake in southwest China kills two with over 7,000 evacuated
Trump warns Iran ‘clock is ticking’ amid rising tensions
1 dead, over 30 injured after Russia launches overnight attack on Ukraine
Cuba accuses US of fabrication after Axios report alleging drone threat
Israeli strikes kill eight people in Gaza, medics say